WO2007093786A1

WO2007093786A1 - Bougie

Info

Publication number: WO2007093786A1
Application number: PCT/GB2007/000508
Authority: WO
Inventors: Paul Wightman; David Green; Stuart Wallace
Original assignee: Owen Greenings & Mumford Limited
Priority date: 2006-02-15
Filing date: 2007-02-14
Publication date: 2007-08-23
Also published as: EP1984054A1; GB0603010D0

Abstract

A bougie (10) is made up of an outer tube (18) surrounding an inner tube (16). Anti-rotation means in the form of equi-spaced ribs (20) on the inner tube (16) are received in corresponding longitudinal grooves (22) provided in the outer tube (18). The ribs (20) interlock in the grooves (22) to prevent relative rotation between the inner and outer tubes (16, 18) so that rotation can be applied from one end to the other with little or no backlash, whilst allowing slight longitudinal slippage when the bougie is bent into shape.

Description

Bougie

This invention relates to a bougie, that is an elongate flexible element designed to be introduced into the body of a patient through, for example, the buccal cavity or the nasal cavity. There are many procedures where it is required to pass a bougie into the body of a patient, and the term 'bougie' is used to cover devices designed to remain in place such as an endotracheal tube, gastric decompression or gastric drainage tubes, as well as those devices used temporarily as a guide to aid insertion of other medical appliances such as endotracheal tubes, etc. Traditional bougies comprise a rod of a gum elastic material which combines stiffness with flexibility at body temperatures. When used for endotracheal intubation, a bougie is directed past the epiglottis and into the larynx and thence into the trachea usually with the use of a laryngoscope. When the bougie has been correctly positioned, an endotracheal tube can be railroaded over it through the larynx and into the trachea. However, it is often difficult to determine whether the bougie tip has actually entered the trachea (correct) or the oesophagus (incorrect).

WO02/09799 describes a single use bougie comprising a catheter with a lumen extending from a connector at a proximal end to an obturated tip with lateral apertures through which gas may pass and through which the gaseous environment adjacent the end of the device may be sampled.

For ease of use and reduction of the risk of infection, it is often preferred that appliances and instruments used in medical procedures are single use. In these instances it is preferred for the appliance to be multi-functional to reduce the number of different items that have to be stocked for theatre use. We have developed a bougie which has sufficient shape memory for it to be used as a traditional bougie for endotracheal intubation or as a tube for passing fluids, solids etc to or from the interior of the patient's body. One of the problems posed to the anaesthetist, who is normally responsible for this procedure, is to be able to shape and steer the tip of the bougie towards the intended destination. It is extremely dangerous if the bougie has entered the oesophagus when intended for the trachea or vice versa. Before insertion into the body, the anaesthetist will normally bend the bougie towards a required curved shape and this often involves pronounced inclination at the tip to provide a coude tip. In order to steer the bougie correctly, it is important that the anaesthetist be able to twist the bougie clockwise/anticlockwise and for this rotational movement to be transmitted through to the tip.

Accordingly, in one aspect, this invention provides a bougie for being inserted into the body of a patient, said bougie comprising:- an inner tube defining a flow passage extending from a proximal end to a distal end thereof; an outer tube generally surrounding said inner tube, and anti-rotation means provided between said inner tube and said outer tube to prevent rotation between the two; the inner tube, outer tube and anti-rotation means providing a malleable, plastically deformable property at least in a generally distal region whereby said bougie may be bent to a required shape, and retain said shape at least temporarily, to assist insertion thereof into a body cavity of the patient. The structure and flexural characteristics of the appliance mean that it can be used as a standard type of bougie making use of the shape memory, or as a drainage tube such as a gastric decompression tube.

Preferably, the anti-rotation means comprise one or more ribs extending along at least part of the length of one of said tubes and being received in a respective groove in the other thereof. The ribs may be conveniently provided on the inner tube, and a plurality of ribs may be equispaced around the inner or outer tube as the case may be. The arrangement of the inner and outer tubes and the anti-rotation means preferably allows slight longitudinal sliding movement between the inner and outer tubes.

This allows a greater degree of shaping of the bougie as it allows relief of the shear stresses at the interface between the inner and outer tubes that would otherwise resist flexure of the bougie. However the interlocking of the ribs in their respective grooves means that rotation may be precisely transmitted along the bougie from where it may be held in use (e.g. in a mid-region) to the distal region.

Whilst the bougie is intended to be shaped along its length to suit the physiology of the procedure and the patient, it is particularly preferred for the bougie to be arranged so that the tip thereof can be bent to retain an angular deflection of at least 40°, thereby provide a coude tip of minimum 40°.

In order to provide a benign, atraumatic tip, the inner tube preferably stops short of the distal end of the outer tube, whereby the distal end of said outer tube projecting beyond said inner tube acts as a relatively flexible atraumatic tip. Conveniently the outer tube is made of a soft, flexible, rubber-like material such as PVC. The inner tube may be made from a stiffer material but one capable of retaining an applied curved shape, such as high-density polyethylene. Preferably the length of the outer tube that projects to provide said atraumatic tip is no greater than 15mm and more preferably equal to about

12.5mm.

We have found that the dimension of 12.5mm is particularly preferred as if the dimension is significantly greater, the tip is too floppy to use as a bougie and this also makes it difficult to form a coude tip shape. With shorter length tips, the tip loses its soft nature which provides the atraumatic feature.

Preferably the distal end of the outer tube is obturated and the portion thereof projecting beyond said inner tube is provided with a plurality of apertures. The apertures preferably are of a maximum dimensional diameter which is less than the inner transverse dimension of the flow passage of the inner tube, to prevent passage into the interior of the tube of material likely to block the inner tube. The apertures conveniently are of the order of 1.5mm in diameter.

Preferably a female luer is connected to the proximal end of the bougie and in flow communication with said passage. To allow the bougie to act in a conventional fashion to act as a guide for a tube to be railroaded over it, the outer dimension of the female luer is preferably less than 6.5mm.

Preferably, a connector device is removably connectable to said female luer to allow connection thereof in use to a suction device. Preferably, the bougie is packaged with said connector device in suitable sterile packaging so as to allow the device to be adapted for use as a standard bougie or as a gastric tube on removal from the packaging.

Whilst the invention has been described above, it extends to any inventive combination of the features set out above or in the following description.

The invention may be performed in various ways, and an embodiment thereof will now be described by way of example only, reference being made to the accompanying drawings in which: Figure 1 is a side view of a multi-function intubating bougie in accordance with this invention;

Figure 2 is a detailed cross-sectional view on the proximal end thereof;

Figure 3 is a detailed cross-sectional view on the distal end thereof;

Figure 4 is a section view through the atraumatic tip of the bougie taken on lines iv-iv, and

Figure 5 is a section view taken further up the bougie on lines v-v.

The device shown in the drawings is intended to be used as a multifunction intubating bougie, capable of being used as an endotrachael tube (ET) intubating introducer or as a gastric decompression tube according to the particular requirement.

The illustrated bougie 10 has a proximal end 12 and a distal end 14. The bougie is made up of an inner cylindrical tube 16 which, in this embodiment, is made of a high density polyethylene material. An outer tube 18 surrounds the inner tube 16 and, in this embodiment, is made of PVC material. As seen in Figures 4 and 5, the inner tube is provided with three equi-spaced ribs 20 which are received in corresponding longitudinal grooves 22 provided in the outer tube. The ribs 20 interlock in the grooves 22 to prevent relative rotation between the inner and outer tubes 16, 18, whilst still allowing slight relative longitudinal movement. At the distal end region 14 the inner tube 16 stops short of the outer tube 18 to provide an atraumatic tip region 24. The soft rubber nature of the outer tube 18 means that the tip is likely to yield if it collides with a tissue wall, thereby avoiding or reducing the likelihood of damage. It should be noted that perforation of the oesophagus or gut is very dangerous. In this embodiment, the length of the atraumatic tip region 24 is approximately 12.5mm. The tip 24 is provided with four holes for the suction of gas or gastric fluid. In this embodiment the diameter of the holes is about 1.5mm, which is smaller than the internal diameter of the inner tube 16 and so the holes 26 act as a filter to prevent particles entering the inner tube of size likely to block it. The material properties of the outer tube, the sizing and spacing of the holes 26 and the wall thickness are designed so that the tip retains its shape and does not unduly distort or crease on insertion (apart of course from inadvertent collision with a tissue wall).

At its distal end 12, the outer tube stops short of the inner tube as shown and a female luer 28 is bonded to the inner and outer tubes. The luer connection is dimensioned so that a 6.5mm endotracheal tube (the smallest applicable tube) can pass over it. The luer 28 allows attachment to a gas sample line and thence to a capnograph so that correct placement of the bougie can be detected by monitoring for presence/absence of CO₂. Releasably connected to the female luer 28 is a suction connector 30 which allows the bougie to be connected to a suction device for use e.g. in gastric decompression. In order to present the device as a multi-function intubating bougie, in relevant embodiments, the suction connector 30 will be packaged in suitable sterile packaging together with the remainder of the bougie.

As seen in Figure 1 , the bougie may also include distance markers 32 to assist the anaesthetist.

In use, the anaesthetist having removed the device from the packaging will apply or discard the suction connector 30 as necessary and then shape the bougie according to the physiology of the patient and the procedure. This will often involve applying a kink or inclination at the distal end so that the last 20 to 25mm are inclined at an angle of somewhere between 40° to 65° to provide a conde tip. We have found that the combination of an outer tube of PVC and an inner tube of high density polyethylene provides sufficient shape memory for a period adequate for the insertion and steering of the bougie.

The interlocking ribs and grooves 20, 22 provide excellent steerability and the longitudinal slippage between the inner and outer tubes allows the bougie to be bent and to hold a suitable curve. Normally the anaesthetist will apply rotation to the bougie by gripping it about half way along its length and then rotating. The interlock feature ensures that the required degree of rotation is transmitted through to rotation at the tip with little or no backlash. This is useful particularly in instances where a coude tip has been formed because it helps in correct placement in the trachea. The two part nature of the device produces the atraumatic tip region but this also produces the softness of the device when rotated.

Claims

1. A bougie for being inserted into the body of a patient, said bougie Gomprising:- an inner tube defining a flow passage extending from a proximal end to a distal end thereof; an outer tube generally surrounding said inner tube; anti-rotation means provided between said inner tube and said outer tube to prevent rotation between the two, and the inner tube, outer tube and anti-rotation means providing a malleable, plastically deformable property at least in a generally distal region whereby said bougie may be bent to a required shape, and retain said shape at least temporarily, to assist insertion thereof into a body cavity of the patient.

2. A bougie according to Claim 1 , wherein said anti-rotation means comprises one or more ribs extending along at least part of the length of one of said tubes and being received in a respective groove in the other of said tubes.

3. A bougie according to Claim 2, wherein relative longitudinal slippage is allowed between the inner and outer tube.

4. A bougie according to Claim 2 or Claim 7, wherein said rib or ribs are provided on the inner tube.

5. A bougie according to any of Claims 2 to 4, wherein a plurality of ribs are equi-spaced around the periphery of said outer tube.

6. A bougie according to any of the preceding Claims, wherein the distal region of the bougie is arranged as to be able the top thereof to be bent to retain an angular deflection of at least 40°, to thereby provide a coude tip of minimum 40°.

7. A bougie according to any of the preceding Claims, wherein said inner tube stops short of the distal end of said outer tube, whereby the distal region of said outer tube projecting beyond said inner tube acts as relatively flexible atraumatic tip.

8. A bougie according to Claim 7, wherein the length of the outer tube that projects is no greater than 15mm, and more preferably equal to about 12.5mm.

9. A bougie according to Claim 7 or Claim 8, wherein the distal end of the outer tube is obturated and the portion thereof projecting beyond the inner tube is provided with a plurality of apertures.

10. A bougie according to Claim 9, wherein the apertures are of maximum dimension or diameter less than the inner transverse dimension of the flow passage of the inner tube.

11. A bougie according to Claim 10, wherein the apertures are circular and about 1.5mm in diameter.

12. A bougie according to any of the preceding Claims, wherein a female luer is connected to the proximal end of the bougie and a flow communication with said passage.

13. A bougie according to Claim 12, wherein the outer dimension or diameter of the female luer is less than 6.5mm.

14. A bougie according to Claim 12 or Claim 13, wherein a connector device is removably connectable to said female luer to allow connection thereof in use to a suction device. B2007/000508

10

15. A bougie according to any of the preceding Claims, wherein said inner tube is made of a high density polyethylene (HDPE).

16. A bougie according to any of the preceding Claims, wherein said outer tube is made of polyvinylchloride.